The invention pertains to a windshield wiper system, in general, and to a windshield wiper system having a wiper and blade assembly and an auxiliary cleaning device, in particular.
A cleaning device of this kind shown in German petty Pat. No. 1,937,591 includes a sponge strip which is relatively hard in its lower area and which may be manually clamped onto the wiper blade by means of wire yokes. The end edge of the sponge strip is thereby flush with the end edge of the wiper lip of the wiper blade. The wiper lip is pivotally connected with the upper areas of the wiper blade via a narrow web. During wiping action the wiper lip must be swivelled relative to the upper areas of the wiper blade and only the longitudinal edges should be moved across the window pane to be cleaned if good cleaning is to be ensured. Swivelling of the wiper lip is not possible, because the relatively hard sponge strip stiffens the system in its lower area. Thus cleaning of the window pane is predominantly effected by the sponge strip. However, as is known, sponge strips do not optimally clean window panes. If the sponge strip becomes worn after a longer wiping service the wiper lip can indeed by swivelled, however then it is solely responsible for cleaning of the window pane.
As a matter of fact a sponge strip of this kind does not improve the cleaning effect of the wiper blade. Moreoveor the view through the window pane during the wiper operation is always impeded by the sponge strip. Furthermore the mounting and demounting of the additional part is inconvenient. This is why cleaning devices of this kind did not succeed in practice.
Another cleaning device is known from the German specification OS No. 2,736,606, in which a wind deflector strip is carried by a wiper arm moving in the same direction as the wiper arm-and-blade assembly. Thus the wiper blade always runs at the lee side of the wind deflector strip and is therefore protected from being lifted. In this case the view through the window pane is impeded by the additional part during all wiping cycles. However at low driving speeds the wind deflector strip is not really necessary, because no airstreams appear which are strong enough to lift the wiper blade. Because the wind deflector strip is always carried by the wiper blade, the drive means are heavily loaded. Such heavy loading can result in premature wear and at least requires a high amount of energy and a correspondingly large drive means.